The goal of the report is an analysis of the behavior of artificial and natural permanent scatterers in the area of Bear Lakes calibration site using ERS SAR data under AO3-343 project. The area of study is calibration site in Moscow region with parabolic antennas (4.7 meters diameter of the dish), which were used over 5 years as calibration targets (artificial permanent scatterers) as well as the Moscow city territory. Our previous analysis of amplitude data has shown very impressive scattering properties and high stability of RCS for such an artificial scatterer, as the large antenna. New stage of current study is focused on long-term amplitude stability as well as phase stability of the scatterers mentioned. Of highest importance is the fact obtained from INSAR studies that such a large ground based calibration target, as antenna, does possess high phase stability (one tenth of the wavelength) in spite of the fact it is affected by pointing errors in every calibration session because of inaccurate predicted ephemeris and errors in the antenna settings. Among the other tasks planned during execution of extension of AO3 project is detection of landslides/subsidence because of technogenic processes to be solved using DINSAR technique. Having extended set of ERS SAR data including archival scenes since 1992 we were able to monitor the stability of the surface in the urban area of Moscow city on the decade time interval. Our preliminary analysis of the ERS DINSAR data shows evidence of the subsidence at the level of wavelength on some restricted areas on the south - east side of the city territory.